.part5{
    margin-top: 20px;
    width: 100%;
    height: 550px;
    position: relative;
}
.bo{
    height: 70px;
    background-color:rgb(69, 69, 70);
}
.t16{
    color:white;
    font-size: 40px;
    font-family: STxingkai;
    position: absolute;
    top: -23px;
    left: 800px;
}
.bo1{
    width: 1000px;
    height: 450px;
    margin-left: auto;
    margin-right: auto;
}
.qq{
    width: 50px;
    height: 50px;
    position: absolute;
    top: 100px;
    left: 580px;
}
.t17{
    position: absolute;
    color:gray;
    top: 150px;
    left: 560px;
}
.wei{
    position: absolute;
    top: 80px;
    left: 860px;
}
.weixin{
    width: 70px;
    height: 70px;
}
.ma{
    width: 100px;
    height: 100px;
}
ul{
    line-height: 50px;
    list-style: none;
}
li{
    width: 100px;
    color:white;
    float: left;
    text-align: center;
}
li:hover{
    background-color:white;
}
ul::after{
    content: "";
    display: table;
    clear: both;
}
.drop{
    position: relative;
}
.menu{
    position: absolute;
    background-color:white;
    width: 100px;
    display: none;
}
.menu a{
    display: block;
    text-decoration: none;
    color:white;
}
.drop:hover .menu{
    display: block;
}
.num{
    width: 50px;
    height: 50px;
    position: absolute;
    top: 105px;
    right: 550px;
}
.t18{
    position: absolute;
    color:gray;
    top: 160px;
    right: 520px;
}
.i1{
    box-sizing: border-box;
    width:400px;
    height: 50px;
    outline: none;
    padding-left:20px;
    border: 1px solid rgb(131, 130, 130);
    position:absolute;
    top: 230px;
    left: 490px;          
}
.i2{
    box-sizing: border-box;
    width:400px;
    height: 50px;
    outline: none;
    padding-left:20px;
    border: 1px solid rgb(131, 130, 130);
    position:absolute;
    top: 230px;
    right: 480px;          
}
.i3{
    box-sizing: border-box;
    width:917px;
    height: 150px;
    outline: none;
    padding-left:20px;
    border: 1px solid rgb(131, 130, 130);
    position:absolute;
    top: 300px;
    left: 490px;          
}
button{
    border:none;
    width:100px;
    height:50px;
    background-color: rgb(184, 183, 183);
    position: absolute;
    top:460px;
    right: 480px;
    color: rgb(94, 91, 91);
}
.back-to {
    bottom: 55px;
    overflow: hidden;
    position: fixed;
}
.back-to .back-top {
    background: url("../img/timg.jpg") ;
    display: block;
    float: right;
    height: 70px;
    width: 70px;
	}